Nanomaterials synthesized with controllable crystallite size, shape, and composition often possess novel properties and provide model systems to understand nanoscience phenomena. Such benefits are evident in the application of nanomaterials towards heterogeneous catalysis, energy conversion, and environmental remediation, just name a few. Given the intimacy between the structural features and functions of nanomaterials, the development of facile synthetic methods for them with controllable growth, especially for those with complex chemical compositions/morphologies in addition to novel and/or enhanced properties, is still an urgent necessity. Molten-salt synthesis (MSS) method is one of those approaches with simplicity, versatility, and cost-effectiveness available for obtaining crystalline, chemically purified, single-phase powders at lower temperatures and often in overall shorter reaction times with little residual impurities as compared with conventional solid-state reactions. While bulk materials have long been prepared using flux method, the preparation of uniform nanostructures using the similar MSS technique has only arisen relatively recently, that is, within the current century. Over the years, our laboratory has applied this method to make various nanomaterials, especially those of transition-metal oxides. In this presentation, various examples will be demonstrated, including materials with perovskite, fluorite, pyrochlore and spinel structures, along with relevant growth mechanism studies and the property measurements of these synthesized nanomaterials. Therefore, the MSS method will continue becoming widely disseminated and broadly adopted as a facile, reliable, and scalable synthetic approach for nanomaterials.

References:

Santosh K. Gupta and Yuanbing Mao, Recent development on molten salt synthesis of inorganic nanomaterials: a review, Journal of Physical Chemistry C, 2021, 125(12), 6508-6533. 10.1021/acs.jpcc.0c10981

Santosh K. Gupta and Yuanbing Mao, Molten-salt synthesis method for nanomaterials: Current status, opportunity and challenges, Progress in Materials Science, 2021, 117, 100734. https://doi.org/10.1016/j.pmatsci.2020.100734